Wanted "ADMIRAL"

[CEBRAIL]

Potentio meter be installed and adjusted instead of r45 39 k

[getsa]

Checking the tressh stability behaviour outside and air test.

https://www.youtube.com/watch?v=I4M8Ds8hE78

[getsa]

... and here's how my latest PCB works - outside the workshop:

https://www.youtube.com/watch?v=ob1nYn2LGC8

Everithing is still very "raw", but for now I'm happy with the result...

Cheers!

[gurdal]

hi all,
RX and TX with aluminum foil shielding

[bonchev2]

Hi gurdal, very nice work can you shared TX & RX data and what wire you used. Greetings and all the best

[gurdal]

Hi gurdal, very nice work can you shared TX & RX data and what wire you used. Greetings and all the best

Hi
TX 1.114 Mh-0.30 330NF
RX 7.15 Mh- 0.60 68NF

[bonchev2]

Thanks gurdal

[bonchev2]

Which one is better guys, aluminum foil shielded coils or graphite?

[CEBRAIL]

Which one is better guys, aluminum foil shielded coils or graphite?

I use graphite

[pito]

I tested both, not much different, I suspect that bad shield is causing more ground influence, so I make coil inside copper tubing = 100% shield.
testing results = The influence of the soil is the same for all 3 of them.

coil inside copper tubing.


to check quality of shielding spray some water on finished coil, no signal changes = good shielding

[Toros]

Hi
TX 1.114 Mh-0.30 330NF
RX 7.15 Mh- 0.60 68NF

This is Admiral1 VLF Metal Detector.
Coil is TX 0,4mm 1mH 330nf, RX 0,25mm 12mH 22nf
Calculated Frequency of 8,7kHz. Null voltage 9mV possible lower with more sens

[bonchev2]

This is Admiral1 VLF Metal Detector.
Coil is TX 0,4mm 1mH 330nf, RX 0,25mm 12mH 22nf
Calculated Frequency of 8,7kHz. Null voltage 9mV possible lower with more sens

RX 22nf ? Strange, what must be frequency of receiver?

[CEBRAIL]

My coils are not affected by graphite coated soil. If the resonance is adjusted well, it goes deep very well. I removed the copper belt lock from a depth of 50 cm. The size is about 3cm

[bonchev2]

My coils are not affected by graphite coated soil. If the resonance is adjusted well, it goes deep very well. I removed the copper belt lock from a depth of 50 cm. The size is about 3cm

Make video I like to see it. Thanks

[getsa]

My coils are not affected by graphite coated soil. If the resonance is adjusted well, it goes deep very well. I removed the copper belt lock from a depth of 50 cm. The size is about 3cm

Hi Cebrail,
What do you mean by adjusting the resonance?
The transmitter is autogenerator - switching the power it started generate sine wave, and if the value of the capacitor changes, it only affects the frequency.
The receiver is an amplifier implemented according to a common base circuit and is a non-resonant circuit. Is it a matter of selecting the capacitor, that is in parallel of the 15k in the emitter of the transistor?
Greetings.